how to make my canon camera lens get in?

I have a few different cameras so to state the obvious I will tell you some of my cameras will not go on with out the sd card or what ever card is required also some of my cameras will but they have built in limited memory. The lens check for a button on the camera and an see if it will release then try to place it back on it may have just come loose and needs to be put on again to make the adjustment follow you book on how to release and replace the lens. Anyway just thought it might help. also, remove the battery and put it back in, unless it is a rechargable bat. that came with the camera then it may not have been charged so you may need to. hope this helps so much for my limited knowledge. GOOD LUCK

V Perez
October 2009